Stretch forming machine with trolley supplied power unit on stretch carriage



Jan. 23, 1962 P. J. NASVYTIS 3,017,916

STRETCH FORMING MACHINE WITH TROLLEY SUPPLIED POWER UNIT 0N STRETCH CARRIAGE Filed Dec. 21, 1959 3 Sheets-Sheet 1 i wrme/vmr INVENTOR @4421 71%,

Jan. 23, 1962 P. J. NASVYTIS 3,017,916

STRETCH FORMING MACHINE WITH TROLLEY SUPPLIED POWER UNIT 0N STRETCH CARRIAGE Filed Dec. 21, 1959 5 Sheets-Sheet 2 Jan. 23, 1962 P. J. NASVYTIS 3,01

STRETCH FORMING MACHINE WITH TROLLEY SUPPLIED POWER uNIT 0N STRETCH CARRIAGE 3 Sheets-Sheet 5 Filed Dec. 21, 1959 INVENTOR.

ATTORNEY.

3,l7,9lb Patented Jan. 23., 1962 fire s 017 are s'rnnrcn FQRMHNG hiaicrrnsn wrrn rnorrinv surrr rsn rowan nun on srnnrcn canmac Pius J. Nasvytis, (Ileveland, @hio, assignor to The tCyrii Bath Company, Aurora, Uhio, a corporation of thin Filed Dec. 21, 1959, Ser. No. 869,796 3 Claims. (til. Edi -40) This invention relates to an improvement in stretch forming machines of the general character disclosed in United States Letters Patent No. 2,514,830, issued July 11, 195i), to Cyril I. Bath, and particularly to a new operating connection between the stretch forming piston and cylinder assemblage and the stock engaging stretching head wherein the usual long and complicated flexible hoses and the like for supplying the hydraulic pressure fluid to the stretch forming assemblage and to other hydraulically operated mechanisms associated with the stretching head, and also long flexible cables for carrying electric power and control currents to various controls associated with the stretching head, are eliminated.

A more specific feature of the invention resides in the fact that the pump and motor for supplying hydraulic power for operating some mechanisms of the stretch forming assemblage are carried on the carriage by which the stretch forming head is carried toward and away from the side face die, and electric power and control currents supplied to mechanisms on the carriage are supplied thereto principally through suitable trolley mechanisms, whereby the usual long flexible hoses leading from a central pump on the machine frame and long flexible electric cables, are unnecessary.

Another feature is to provide a stretch forming machine, including a side face die support, wherein the stretch forming head is carried on a carriage which is movable relatively toward and away from the die support, along a track or guideway, a hydraulic cylinder extends endwise of the track and is movable with the carriage, a double-ended piston is recipro-cable in the cylinder and has its ends connected in fixed relation to the track so that the hydraulic forces applied to the piston for urging the carriage in opposite directions, maintain the piston rod in tension. This arrangement of the piston and cylinder assemblage also affords other advantages in cases of machines in which the carriage must travel along distances in a direction toward and away from the die support.

Another feature resides in the manner of connecting the cylinder to the carriage for travel therewith and for relieving the cylinder from excessive strains due to the weight and long overhang.

Another object is to provide a trolley system for electric control currents for the mechanisms on the travelling carriage, whereby effective remote control can be obtained.

Other objects and advantages of the invention will become apparent from the following description wherein reference is made to the drawings, in which:

FIG. 1 is a top plan view of a stretch forming machine embodying the principles of the present invention and including a hydraulic power diagram;

FIG. 2 is a front elevation of the machine illustrated in FIG. 1;

FIG. 3 is an enlarged vertical cross sectional view taken on the line 33 of FIG. 2;

FIG. 4 is an enlarged fragmentary front elevation of a length of the trolley track, part thereof being broken away to show the trolley thereon in side elevation;

FIG. 5 is an enlarged vertical cross sectional view of the trolley track with the trolley shown thereon in end elevation, and is taken on line 55 of FIG. 4;

FIG. 6 is an enlarged fragmentary side elevation of the stretch forming piston and cylinder assemblage, part thereof being shown in section;

FIG. 7 is a hydraulic diagram illustrating the opera-= tion of the mechanism for operating the clamping jaws of the stretch forming head; and

FIG. 8 is a hydraulic diagram of the drive of the stretch forming piston and cylinder assemblage.

Referring to the drawings, the machine is shown as one in which the stretch forming mechanism is arranged to be swung relatively about the face of the side face die.

Since, on the very long machines, it is preferable that the frame be held stationary and the table rotated, the machine shown for illustration is one wherein the supporting mechanism for the carriage is mounted on the stationary frame and the table which supports the die is rotatably mounted on the same frame.

Referring specifically to the drawing, the machine comprises a generally horizontal frame 1 on which a turntable 2 is mounted on a suitable post 3 for rotation about an upright axis. The table carries a concentric ring gear 4 which is engaged by :a pinion gear 5 on the output driven shaft 6 of a secondary gear reducer 7. The secondary gear reducer is driven, in turn, by a primary gear reducer 8 which is driven by a pair of variable speed reversible hydraulic motors 9 settable hydraulically by control pressure fluid supplied by remote control valves 9a. Operating pressure fluid is supplied by a pump 10 driven by an electric motor 1'1. These hydraulic motors are operable to provide variations in speed of the table such that the table can be driven throughout a wide range of speeds of which the lowest is one in which the table creeps almost imperceptibly. The frame has an elongated portion 12 extending radially from the table and comprises essentially a pair of girders 13 arranged in fixed and laterally spaced face to face relation to each other on suitable cross tie members 14. Mounted on the members 13 are trackways, later to be described, for a stretch forming carriage 20.

The stretch forming carriage 20 is provided with front wheels 21 and rear wheels 22 which are operative on tracks 23 and 24, respectively. Suitable guide rolls 25 are arranged at opposite ends of the carriage and engage the inner edges of guide rails 26 which are arranged to serve not only as guide rails but also as hold-down rails for the rear rollers 21 of the carriage 2i Mounted on the carriage is an upright pivot post 30 on which a sleeve 31 is rotatably mounted. Connected to, and extending radially from, the axis of the sleeve 31 for swinging about the axis of the post 30 is a stretch forming arm 33 which extends from the sleeve back toward the table 2 in overhanging spaced relation to the carriage, and which, at its outer or free end, carries a fixed plate 34. A stretch forming gripping head is carried on the plate 34. The head may be of the remotely controlled hydraulically operated clamping jaw 3 type so that it can be operated from a point remote from the head to grip or release the stock, as will later be described.

The arm 33 is elongated so as to be suitable for use with an elongated load cell, as more fully described in the copending applications of Perkins and De Marco, Serial No. 858,376, filed December 9, 1959, and executed November 23 and December 5, 1959, and Cyril J. Bath, Serial No. 858,967, filed December 11, 1959, and executed November 6, 1959. On the outer end of the arm are suitable skid plates 36 cooperable with corresponding skid plates 37 on the carriage for supporting part of the overhanging weight of the arm on, and relieving the arm from, vertically directed flexure stresses.

In order to reciprocate the carriage 28 so as to apply yieldable stretch forming tension to the stock to be formed as it is wrapped about a side face forming die D on the table 2, a suitable cylinder 44) is provided. The cylinder 40 extends endwise of the tracks 23 and 24 and is secured to the carriage 20 for movement therewith endwise along the tracks in endwise fixed relation to the carriage. However, since the stresses and forces on the carriage may tend to cause rocking movement of the carriage and deflection thereof vertically and transversely of the tracks, the cylinder 40 is connected to the carriage by a swivel connection so that it can maintain its proper position in axial alignment with its starting position during reciprocation of the carriage. For this purpose, a bracket 42 is fixedly secured to the cylinder 48 near one end of the cylinder. The bracket 42 is pivotally connected to a link 43 in a conventional manner for rocking relative thereto about a horizontal axis, as illustrated in FIG. 2. The other end of the link is correspondingly pivotally connected to a securing bracket 34 on the carriage. The link is a conventional swivel link, thus allowing the slight rocking of the carriage about the axis of the cylinder, in addition to vertical movement of the cylinder relative to the carriage.

To relieve the carriage of the weight of the cylinder and the cylinder from deflecting forces due to its own weight, the cylinder, at the end farther from the table in the retracted position of the carriage 20, is connected to, and rests on, a suitable saddle 50 having rollers 51 which roll along the track 24.

At its opposite end which is nearer to the table in the retracted position of the carriage, the cylinder is provided with a depending roller 53 which is arranged to roll on a track 54 which extends partway lengthwise of the frame 1 parallel to the tracks 23 and 24. Thus the opposite ends of the cylinder 40 are supported suitably and anti-frictionally on trackways so that the cylinder is relieved from any excessive vertical deflection stresses resulting from its weight.

Mounted in the cylinder is a double-end piston 56 having oppositely extending hollow rods 57 and 58. The rods 57 and 58 have ports 57:: and 58a adjacent to the opposite sides, respectively, of the piston 56 for communicating the interiors of the rods with the interior of the cylinder 40. The rods 57 and 58 are fixedly connected to the ends of the frame of the machine and are connected to rigid fluid pressure supply pipes 59 and 60, respectively. Thus, by admission of pressure fluid to one side of the piston 56 in the cylinder 40, the carriage is urged away from the table and, by admission of pressure fluid to the opposite side of the piston, the carriage is urged toward the table.

The forming of the stock is occasioned by gripping one end of the length of stock S in the conventional hydraulically operated jaws of the stretch forming head 35, and the other end in a suitable clamp 61 which is mounted on the table 2 for rotation therewith in fixed relation to the die D. The stretch forming operation is performed in essentially the manner described in the above United States Letters Patent No. 2,514,830. The jaws of the head 35 are manipulated by a hydraulic piston and cylinder assemblage 62 mounted on the head 35.

In order to supply pressure fluid to the assemblage 62, a variable delivery hydraulic pump 64 and its electnc driving motor 65 are mounted on the carriage 20 in fixed position relative to the arm 33 for swinging therewith. A sump tank 66 for the pump and hydraulic circuit is mounted in the carriage 28. By this arrangement, the pump can be connected by rigidly fixed pipes 67 and 68 to opposite ends of the cylinder 62, respectlvely, the pump being connected to these lines through a conventional remotely controlled reversing control valve 69, later to be described. Long flexible pressure fluid conduits and hoses are eliminated.

If, as in U.S. Patent No. 2,806,505, issued September 17, 1957, it is desired to raise and lower the stretch head by a hydraulic assemblage, or any other mechanisms on the arm 33 to be operated hydraulically, direct connections may be made thereto from the pump 64.

The motor 65 is an electric motor and a number of the controls utilized in connection with the carriage and the stretch forming mechanisms thereon are electric. Accordingly, it is necessary to supply electric power and control currents to the mechanisms on the carriage. For this purpose, suitable track supports 70 and 71 are mounted on a frame member 13 at a location below the carriage 28. The track support 70 carries suitable tracks 72, and the track support 71 carries a suitable track 73. Trolleys 74 are arranged to operate on the tracks 72, respectively, and are connected by suitable electric cables enclosed in a conduit 76 to the various mechanisms on the carriage. The main motor 65 employs a much higher voltage and, therefore, is connected by a separate cable to a trolley 78 which operates on the track 73.

The tracks 72 and 73 are held in fixed position end-wise of the frame. Since all of the tracks and trolleys are the same, except for size, in form and function, only one will be described in detail.

As illustrated in FIG. 5, each track 72 comprises in general an inverted housing 89 open at the bottom and having at the bottom two inturned flanges extending inwardly toward each other and terminating in spaced relation to each other transversely of the housing 80. These flanges provide tracks 81. Each trolley comprises a carriage 82 having supporting wheels 83 operating on the tracks 81, and a centering and guide wheel 84 for maintaining the trolley in proper position laterally for endwise travel along the tracks 81.

Each housing carries three bus bars 85 and each trolley carries three pairs of contacts 86 arranged so that the pairs operate along the bus bars 85, one pair to each bus bar, respectively. The trolleys, as mentioned, are connected through the rigid conduit 76 for movement with the carriage 28 as the carriage moves along its supporting trackways 23 and 24. Thus, there are means for providing electrical connections at all times between those mechanisms carried on the carriage and the central control panel through the media of a fixed cable on the carriage, the trolleys, and the bus bars 85.

Referring to FIG. 7, the motor 65 is connected through suitable leads to the trolley 78, the bus bars for which are connected to a source of power, indicated by lines L and L by way of a control panel 88, through a suitable switch 89. Thus, through the switch 89 and the trolley 78, and its bus bars, the motor M can be started and stopped.

As mentioned, the pump 64 preferably is a variable displacement pump so that discharge may be controlled directly by an electrically operable control 90. If it is desired to control the pump 64 from the panel 88, this may be done by a suitable control device 91 mounted in the panel and electrically connected to the control through one of the bus bars of one of the trolleys 72. Again, the valve 69 for the jaw cylinder 62 can be operated by suitable solenoids 93 which are controllable by a suitable control device 94 in the control panel to which the solenoids are connected electrically, respectively, through others of the bus bars and their trolleys 72.

The control of the stretch forming piston and cylinder assemblage is illustrated diagrammatically in FIG. 8. As there illustrated, the lines 59 and 60 are connected to a three position, four-way valve 95, which may be operated remotely by suitable solenoid controlled piston and cylinder assemblages 96, or manually, if desired. Pressure fluid is supplied to the valve 95 from a pump 97 driven by a motor 98, the pressure being controlled by a suitable relief valve 99.

The valve 95 operates in one position to admit pressure fluid to the cylinder at one side of the piston 56 through the rod 57 and vent the cylinder at the opposite face of the piston 56 through the rod 58, and in another position to reverse the connection.

This makes possible both the movement and the resistance to movement of the carriage 20 by the piston 56 in a manner such that, at all times, the hydraulic force acts through a piston rod under tension. In no case are the piston rods placed under compression and hence the piston and cylinder assemblage is not subjected to compressive forces which would tend to cause a column effect, such as buckling and binding of the assemblage.

In the prior structures in which the cylinder was carried on the carriage so as to eliminate this buckling effect, considerable difliculty was encountered in case of very long pieces to be formed. This was because the movement of the cylinder of the carriage was considerable and necessitated the use of long flexible hoses for conducting pressure fluid from the source to the opposite ends of the cylinder. Such hoses impose a considerable problem inasmuch as, for a given pressure delivered by the pump, the pressure delivered by the hoses varies depending upon their degree of flexure and sharpness of bend. The bending and flexing of the hoses necessarily introduces variations in the flow of the hydraulic pressure fluid. The variables introduced by long flexible hoses in the pressure line are often unpredictable and inconstant.

By combining the mounting of the cylinder on the carriage and introducing the pressure fluid through the ends of a double-ended piston connected to the frame, the flow characteristics into the cylinder at either side of the piston can be kept constant regardless of the position of the cylinder and carriage along the path of travel of the carriage. This greatly facilitates the control of the tensioning of the stock and, since a number of variable factors must be taken into consideration in controlling the tension applied to the stock, the elimination of variables arising from the piston and cylinder assemblage itself and from a flexible hose fluid supply circuit, contributes greatly to simplification of control of the fewer variable factors remaining.

By mounting on the carriage the fluid pressure supply for operating those things carried on the carriage and particularly by mounting the fluid pressure supply on the carriage through the medium of the pivoted support for the arm 33 so that it swings with, and in fixed position relative to, the arm 33, additional variables are eliminated, as rigid, short, and fixed pipes are used instead of long flexible hoses which latter must be flexed continuously during different degrees of the travel of the carriage and swinging of the arm 33.

The placing of the stretch forming piston and cylinder assemblage at all times under tension instead of at times under tension and at times under compression further eliminates variable friction and binding stress which would be continuously changing and would have to be compensated for, thereby further complicating control of the tension applied to the stock.

If tension control is desired, it may be efliected as disclosed in US. Patent No. 2,849,048, issued August 26, 1958, in response to a load cell 100 having a strain gauge 101 connected to a suitable amplifying tension signal control unit 102 on the carriage which receives and amplifies electrical tension signals from the strain gauge 101. These signals, after amplification, are carried by another one of the trolleys 72 and one of its bus bars to a suitable control device on the control panel 88.

It is to be pointed out that the specific mechanisms on the carriage to be controlled depend on the work to be performed and may be varied without departing from the concepts of the present invention which reside pri-r marily in the manner of supplying the pressure fluid to the stretch forming assemblage, the manner of providing on the carriage the pump and the motor so as to eliminate long flexible pressure conduits for operating mechanisms on the carriage, and the provision of a means for supplying electric power, control currents, and signals to various mechanisms on the carriage through the introduction of guarded trolleys and bus bars.

Having thus described my invention, I claim:

1. In a stretch forming machine, a frame, a power driven turntable rotatably mounted thereon and adapted to support a side face die, a stretch forming carriage mounted on the frame for movement toward and away from the table, a stretch forming head adapted for connection to an end of a length of stock for applying tension to the stock endwise for stretch forming it about the die, means connecting the head and carriage for movement together toward and away from the turntable, power means for controlling the movement of the carriage toward the table, clamp means for connecting the stock, at a location spaced from said end, for movement with the table, a hydraulic pump on the carriage, an electric motor on the carriage operable for driving the pump, hydraulic motor means connected to the head for effecting a predetermined operation of the head, hydraulic circuit means on the carriage and connecting the pump to the hydraulic motor means for operating the hydraulic motor means, conductor means for supplying electric power to the electric motor, said conductor means including a trolley movable with the carriage and electrically connected to the motor, and trolley line means connecting the trolley to a source of electrical power.

2. In a stretch forming machine, a frame, a power driven turntable rotatably mounted thereon and adapted to support a side face die, a stretch forming carriage mounted on the frame for movement toward and away from the table, a stretch forming head adapted for connection to an end of a length of stock for applying tension to the stock endwise for stretch forming it about the die, connecting means connecting the head and carriage for movement together toward and away from the turntable, power means for controlling the movement of the carriage toward the table, clamp means for connecting the stock, at a location spaced from said end, for movement with the table, a hydraulic pump on the carriage, an electric motor on the carriage operable for driving the pump, hydraulic motor means connected to the head for effecting a predetermined operation of the head, hydraulic circuit means on the carriage and connecting the pump to the hydraulic motor means for operating the hydraulic motor means, conductor means for supplying electric power to the electric motor, said connecting means which connect the head to the carriage including a member swingable about an upright axis relative to the carriage, and the electric motor, hydraulic pump, and the hydraulic motor means for the head and the hydraulic circuit connections between the pump and hydraulic motor means being mounted on said member.

3. In a stretch forming machine, a frame, a power driven turntable rotatably mounted thereon and adapted to support a side face die, a stretch forming carriage mounted on the frame for movement toward and away from the table, a stretch forming head adapted for connection to an end of a length of stock for applying tension to the stock endwise for stretch forming it about the die,

a means connecting the head and carriage for movement together toward and away from the turntable, power means for controlling the movement of the carriage toward the table, clamp means for connecting the stock, at a location spaced from said end, for movement with the table, a hydraulic pump on the carriage, an electric motor on the carriage operable for driving the pump, hydraulic motor means connected to the head for eifecting a predetermined operation of the head, hydraulic circuit means on the carriage and connecting the pump to the hydraulic motor means for operating the hydraulic motor means, conductor means for supplying electric power to the electric motor, an electric control means being carried on the carriage for controlling a n1ech- 8 anism on the carriage, a trolley movable with the carriage and electrically connected to the control means, and trolley line means connecting the trolley to a source of control power.

References Cited in the file of this patent UNITED STATES PATENTS 2,026,884 Glasgow Jan. 7, 1936 2,254,147 Horn Aug. 26, 1941 2,479,995 Barriger Aug. 23, 1949 2,514,831 Bath July 11, 1950 2,550,925 Weirnar May 1, 1951 2,743,756 Fredericks May 1, 1956 2,849,048 Curtner Aug. 26, 1958 

